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Owen Maroney worries that physicists have spent the better part of a century engaging in fraud.
Ever since they invented quantum theory in the early 1900s, explains Maroney, who is himself a physicist at the University of Oxford, UK, they have been talking about how strange it is — how it allows particles and atoms to move in many directions at once, for example, or to spin clockwise and anticlockwise simultaneously. But talk is not proof, says Maroney. “If we tell the public that quantum theory is weird, we better go out and test that's actually true,” he says. “Otherwise we're not doing science, we're just explaining some funny squiggles on a blackboard.”
It is this sentiment that has led Maroney and others to develop a new series of experiments to uncover the nature of the wavefunction — the mysterious entity that lies at the heart of quantum weirdness. On paper, the wavefunction is simply a mathematical object that physicists denote with the Greek letter psi (Ψ) — one of Maroney's funny squiggles — and use to describe a particle's quantum behaviour. Depending on the experiment, the wavefunction allows them to calculate the probability of observing an electron at any particular location, or the chances that its spin is oriented up or down. But the mathematics shed no light on what a wavefunction truly is. Is it a physical thing ? Or just a calculating tool for handling an observer's ignorance about the world ?
http://www.nature.com/news/quantum-physics-what-is-really-real-1.17585
(Score: 5, Insightful) by physicsmajor on Friday May 22 2015, @05:50AM
Maroney should be up in arms about this. Specifically, about the first sentence which invokes the scientific F-bomb: fraud. He never, ever said that word... and by publishing that sentence Nature is fueling the "scientists don't know anything!" mindset which is eroding the credibility of real experts everywhere, paving the way for anti-vaxxers and disbelief in climate change. If I were him, I would be drafting some incredibly strong-worded emails to the Nature Group.
There is absolutely nothing fraudulent about quantum theory. Nothing. It may seem weird, sure, but it produces testable predictions, all of which to date have been verified. This isn't just me saying as much, either - you, too, can experimentally verify the wavefunction is a real thing with as little as a laser pointer and two pieces of cut and polished glass.
Maroney is saying that some more experiments to probe these effects would be a good idea. Great! It sounds like they managed to do some experiments and found an unexpected discrepancy. That's fantastic! It means we might need to find a new theory, or modify the existing one. Note though that the result must not only can explain everything else but also the new findings. This never once says or implies that everything prior to this point was wrong! At the very, very worst it's wrong like Newton's theories were - essentially correct within experimental limits until we could actually think about things on the scale necessary to come up with Relativity. EVEN IF - and it's a very strong if - quantum theory isn't entirely correct, it's at least good enough to explain everything we've tested and used it for to date. Including the sub-wavelength masks necessary to produce the silicone chips running the device you're reading this on.
I'm guessing their freelance contract writer wanted to juice up the story a bit, and instead of smacking her hand the editors of Nature were asleep at the wheel for this one. Shame on them.
(Score: 0) by Anonymous Coward on Friday May 22 2015, @06:19AM
Amen to that. I could not have said it better myself.
Well, to be fair, it is almost certain that there are some gaps to either relativity or quantum theory (or both). We still don't have a grand unified theory yet. Other than that, I agree completely.
(Score: 2) by hubie on Friday May 22 2015, @01:05PM
It doesn't point to shortcomings in quantum or relativity if there is no grand unified theory.
(Score: 2) by HiThere on Friday May 22 2015, @06:36PM
If a Grand Unified Theory is impossible between Relativity and Quantum Theory, then both must be incorrect. This doesn't say what the replacement should look like, though. A Grand Unified Theory would have either Relativity swallowing Quantum Theory, or Quantum Theory swallowing Relativity...but it's not clear how to do this.
One unfortunate possibility is that the only possible Grand Unified Theory has no testable predictions. For awhile it looked like string theory was going to be such a theory, but that currently looks less likely (to me. OTOH, I am not a physicist).
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by hubie on Friday May 22 2015, @07:02PM
No, you are assuming a grand unified theory exists. If one doesn't exist, that doesn't say anything about quantum and relativity. The most compelling case that a GUT exists is purely on aesthetic grounds. We like simplicity and elegance in our theories.
(Score: 2) by boristhespider on Friday May 22 2015, @07:39PM
Pure pedantry, but GUTs combine the electroweak theory with the strong theory. A so-called Theory of Everything combines a (postulated) GUT with gravity. I'd note that we do not actually have a single, accepted GUT yet. The idea that the only force to lie outwith a unified theory is gravity is something of a fallacy, although it's certainly the only theory to lie outwith various extensions that are generally accepted as well-enough motivated.
(Score: 2) by hubie on Friday May 22 2015, @07:51PM
I am being careless between GUTs and ToEs (and whatever the hell other stupid acronyms that come next), but my intention was to talk of unified theories in general. All I'm saying is that it may turn out that you cannot combine all the forces into some nice compact model.
(Score: 3, Informative) by boristhespider on Friday May 22 2015, @08:01PM
Totally agreed. I've maintained for a number of years - from when I was an undergraduate all the way through a career in post-doctoral cosmology - that there is no a priori reason to assume that we can combine all four forces, particularly as only two of the four manifest themselves on macroscopic scales, and we are attempting to force all four into a formalism that was developed for electromagnetism, which unlike gravity actually acts like a force.
Frankly, since gravity doesn't behave like a force macroscopically, trying to shoehorn it into a theory developed for something that *does* behave like a force has always struck me as a bit odd. Yes, we can derive (linearised, classical) gravity by postulating a massless, spin-2 particle but I view that as little more than a mathematical curiosity. Hell, we can barely force together the strong force and the electroweak force, scuppered this time by the strength of the coupling of the strong force that pushes out of what is effectively just a Taylor series. Jumping the gun ridiculously by trying to shoehorn in something that may or may not provide a sane description of macroscopic gravity and which is even in vacuum nigh on impossible to renormalise isn't so much biting off more than we can chew as stuffing our gullets with styrofoam.
(Score: 2) by hubie on Friday May 22 2015, @08:56PM
But that is where the Nobels are!! :)
I never had to venture very far into cosmology, but that whole renormalization business always sounded unsettling to me (probably because I never sat down and did the math myself).
(Score: 2) by boristhespider on Friday May 22 2015, @09:20PM
About twelve years back in the university library I read through the three-volume "History of Quantum Field Theory", or whatever it was called, in lieu of revising for my exams. In these volumes no less than Schwinger commented something like, "I'm not sure that renormalisation is mathematically justifiable" (it is, arguably; but not the way it's normally presented), while Feynman was quoted as saying, to extraordinarily loosely paraphrase, "Physics is ultimately algorithms and there's no reason to assume that algorithms that work in one situation apply in another; there is therefore no reason to immediately assume we will ever find a theory of everything".
I'll be back in my old uni town next month. I'm tempted to try and blag my way into their library so I can track down those books again and find Feynman's quote in particular because it's influenced me very strongly. (The only other thing that's influenced me as strongly was Peebles, in a talk in Paris in 2004 or so, who pointed out that modern cosmology wants us to believe that 5% of the universe is made of the standard model(ish) - whose Lagrangian fits on a side of paper - while 25% and 70% respectively are meant to be two types of matter whose *entire physical description* are w=0 and w=-1. Peebles wasn't so much attacking dark matter and dark energy (although he was criticising the tendency to assume them), but commented "I don't like this description of dark matter in cosmology and *I introduced it*" (which is basically true). The point was more that while we might have phenomenological descriptions, there's no way that the *physics* of 75% of the universe is as simple as cosmology might say.
(Score: 1, Informative) by Anonymous Coward on Friday May 22 2015, @10:00PM
While an unification of the different quantum field theories is not strictly necessary (the standard model works quite well), it is a completely different thing with the unification of quantum field theory with general relativity: While the different quantum field theories are compatible, quantum field theory and general relativity aren't. That is, there is no way both theories can correctly describe the world in all cases. The main problem is that the areas where they conflict are far beyond our (current, and for a long time also future) experimental ability, so we cannot simply make experiments to decide what really happens in the "conflict zones".
(Score: 1) by khallow on Saturday May 23 2015, @03:16AM
It doesn't point to shortcomings in quantum or relativity if there is no grand unified theory.
If your theory doesn't explain everything perfectly, then it has short comings, though not necessarily short comings that anyone cares about. Here, people care that QM and relativity don't explain the middle ground between the two theories.
(Score: 0) by Anonymous Coward on Friday May 22 2015, @06:53AM
nature@nature.com
(Score: 2, Insightful) by Anonymous Coward on Friday May 22 2015, @07:56AM
Of course it is. A theory that (in general terms) says that every option happens at the same time, and only at the time of observation will a random option be chosen, is good enough to explain just about anything.
(Score: 1, Funny) by Anonymous Coward on Friday May 22 2015, @07:58AM
Hey don't get smart now!
We don't want you waking up to the fact they've spent shit loads of money to prove we can only chase our tails.
(Score: 1) by khallow on Friday May 22 2015, @08:19AM
A theory that (in general terms) says that every option happens at the same time, and only at the time of observation will a random option be chosen, is good enough to explain just about anything.
Depends what "every option" means and how those options are weighted. Also, your statement is not quantum mechanics, but a model of how we think we observe some particular model of quantum mechanics.
(Score: -1, Flamebait) by Anonymous Coward on Friday May 22 2015, @08:08AM
The real issue is that physicists, including yourself, act in attitude one way and when challenged become highly technical, backpedaling with frightening speed. Quantum theory is right, quantum theory explains this thing and that thing, but when pressed it is found that such statements are emotional in nature and not factual. Really with all the high-flying statements about quantum theory ending encryption as we know it and the like without the slightest bit of real-world evidence except squiggly lines on a chalkboard, it certainly does begin to look fraudulent, doubly so when grand statements are reversed through technical language such as what you are using now.
(Score: 1, Insightful) by Anonymous Coward on Friday May 22 2015, @01:13PM
The bigger problem is that you don't really understand science in the grand scheme of things. Real science is highly technical and very nuanced. You need to talk in very precise language. It is people like you who demand sweeping generalizations, then run around crying the emperor has no clothes because your overgeneralizations don't apply to a specific case. The grand irony is your casting stones at quantum theory by using electronic devices that could only have been invented based upon that theory. You need to keep in mind that sometimes when you don't understand something, that doesn't mean there is something wrong with that something, but rather it has more to do with your personal shortcomings in that area.
(Score: 2) by physicsmajor on Friday May 22 2015, @04:07PM
You completely failed to read/understand what I wrote. As I very clearly state, there is nothing wrong with QM. I cast no stones, and in fact the very example you appear to have misread or misinterpreted was included specifically because of the direct success of predictions made by QM.
It appears you're projecting, and I dismiss ad hominem attacks. Please make at least three attempts to read and understand what I wrote before you post again.
"Real science" isn't just impenetrable technological terms, spiced up with run-on sentences and bad grammar. It's at least as important to properly and correctly convey the findings to the public. Randal Munroe's new book Thing Explainer uses just most common 100 words in the English language to explain very technical things. He's close to taking things to the absurd, but the point is that you can explain these things to lay people and that empowers both the work and the public.
Is there anything else I can help you with?
(Score: 1, Touché) by Anonymous Coward on Friday May 22 2015, @07:07PM
Are you sure you are responding to me, or did you mean to respond to the AC before me (the one who answered you directly)? You could help by reading my response to that AC and see that I am generally in agreement with you. However, you might need to read it three times to see that.
(Score: 0) by Anonymous Coward on Saturday May 23 2015, @01:44AM
Thus my criticism of not using precise language to make claims (the attitudinal part), then using them to defend claims. We are saying the same thing but were moderated in different directions.
(Score: 0) by Anonymous Coward on Friday May 22 2015, @01:58PM
You fell victim to new-age hocus focus quantum this relativictic that. Take a basic course on QM and you'd be better equipped to smell out the bullshit in pop media.
(Score: 2) by physicsmajor on Friday May 22 2015, @03:57PM
Which is... exactly what I did. And I have.
Methinks you failed to read or understand what I wrote.
(Score: 0) by Anonymous Coward on Friday May 22 2015, @05:56PM
Calm down, fool - you got mixed up who's responding to whom.
(Score: 0) by Anonymous Coward on Friday May 22 2015, @07:10PM
I don't think he is viewing at the -1 level because he went off on me when I replied to the AC who is currently sitting at -1. Good to see he pops off on others too. I was starting to think it was just me he didn't like. Boy, with friends like that . . .
(Score: 0) by Anonymous Coward on Friday May 22 2015, @07:16PM
Methinks you shouldn't so vocally cast aspersions on other's reading comprehension when you demonstrate multiple times that the comprehension issue is with yourself (Protip: make sure you can see ALL the comments AND WHO WROTE THEM before firing off condescending responses). Oh, and, er, ad hominem!!! (I felt compelled to throw that in as it seems to be what you are supposed to say to cut off someone's argument).
(Score: -1, Troll) by Anonymous Coward on Friday May 22 2015, @11:41AM
It IS fraudulent because Quantum theory was proposed by the Illuminati as a way to obfuscate the true simplicity of Real Physics in order to insure that only their chosen members would be in possession of the actual truth.
Full understanding of Real Physics would provide far more power to the masses than they ever want them to have.
(Score: 2) by joshuajon on Friday May 22 2015, @05:43PM
you, too, can experimentally verify the wavefunction is a real thing with as little as a laser pointer and two pieces of cut and polished glass.
I have those things! Please tell me more!
(Score: 3, Informative) by boristhespider on Friday May 22 2015, @07:55PM
Entertainingly, and in the original spirit of quantum mechanics, no you can't. What you can do, with a laser (no need for anything else; the existence of the laser itself is proof enough - or the computer you're typing on), is verify that the *predictions* of quantum mechanics are unquestionable in the regimes we work in.
The original formulations of quantum mechanics were first Heisenberg's matrix mechanics and then Schroedinger's wave mechanics. They worked from different motivations - Heisenberg was open about simply taking everything he knew was observable, things he knew existed in classical mechanics, and dicking around with them until he found things that related them, which turned out to basically be matrix multiplication with the operators being generalisations of things that exist in classical mechanics. (Ultimately, one can write Heisenberg's quantum mechanics as Hamiltonian classical mechanics with hats on top of the Hamiltonian, and replacing the Poisson brackets with commutators - that is, replacing {A, B} with [A, B].)
Schroedinger, on the other hand, worked from the de Broglie conception of a wave associated with each particle. A bit of generalisation -- ultimately, replacing the momentum with a differential operator, which is motivated by looking at the momentum of a wave itself -- and you can turn energy conservation into the Schroedinger equation.
These two formulations are equivalent not in that they actually map one onto the other - since they don't, and anyone claiming they do, directly, is fibbing - but because the *observables* that they predict are exactly, and demonstrably, equivalent.
In the same way, other formulations of quantum mechanics are exactly equivalent. In particular, the Bohmian formulation is completely observationally indistinguishable from the so-called Cophenhagen interpretation. Bohmian mechanics is a "hidden variables" theory, and it arises from looking at Schroedinger mechanics, which features the wavefunction, and refusing to accept that the wavefunction is somehow sacresanct. If we take the wavefunction, which is complex-valued, and represent it as a (real) amplitude multipled by a (real) phase factor - as we can; any complex number can be written as z = x*exp(iy) with real x and real y - then we very rapidly recover equations that are extremely simlar to those of normal, classical fluid mechanics: the amplitude of the wavefunction (x^2), becomes a density, and takes part in a fluid continuity equation - that is, conservation of mass. (This is easily explicable as conservation of probability; what I've written as x^2 is normally simply interpreted as the probability of a particle appearing at that position.) But the phase - what I've written as y - appears in an interesting equation that can be interpreted as one of a Hamilton-Jacobi equation or a Bernoulli equation, for a perfectly normal particle, but with a weird extra term. That weird extra term is known as the "quantum potential" or the "quantum pressure" and is the *only difference* between a classical fluid and a quantum fluid. Bohmian mechanics involves reversing this argument and postulating the existence of the quantum potential from the start. The immediate result is a Schroedinger equation, and a theory that is utterly and irrevocably indistinguishable from quantum mechanics, but is absolutely opposed to the usual, probabilistic, Copenhagen interpretation.
TL;DR no you can't - you can merely demonstrate the applicability of the theory. The very formulations of the two classic representations of quantum mechanics are completely different, and other, wildly different, formulations are possible, and give exactly the same results.
(Score: 1) by dingus on Friday May 22 2015, @09:56PM
So you're saying that all of quantum mechanics is unprovable because multiple mathematical models can describe it? That just means there's some hidden relationship between the models, not that the models are untrue. For instance, you can describe the motion of a pendulum either with conservation of mechanical energy or with newtonian forces, and the two can be related with some calculus that isn't usually taught in first-year physics.
(Score: 3, Informative) by boristhespider on Friday May 22 2015, @10:12PM
Not in the slightest. I'm saying that cleaving to one particular model of quantum mechanics is a matter of taste and aesthetics. Also, the conservation of energy (of any sort) is an intrinsic part of Newtonian mechanics. Given the postulates of Newtonian mechanics I can derive the conservation of energy; equivalently, given the "Lagrangian" of Newtonian mechanics (a scalar function describing the paths that particles moving according to the theory can traverse) I can derive conservation of energy, conservation of momentum, conservation of angular momentum, Newton's first, second and third laws, and etc.
The theories I'm talking about that give rise to identical observations are genuinely completely different theories. Their only link is that they produce the same observations - which means that they describe the same physics. The Lagrangians are different, the equations of motion are different, the motivations are different and the interpretations are different. The only link is they describe the same observable consequences.
It doesn't at all mean that QM is unprovable. It means that if anyone says that the Schroedinger description has been proven, they're talking out of their bums. What they're saying is that something predicted by the Schroedinger description has been observed - but that can equally be described in Heisenberg mechanics, and different interpretations open up any number of ways of interpreting those predictions.
(Score: 3, Informative) by boristhespider on Friday May 22 2015, @10:17PM
Ultimately, what I'm saying is that if it doesn't refer to an observable quantity - potential or realistic; that's a different matter - then it isn't describing physics so much as the internals of a physical theory or, if there *are* no observables, maths that is at the boundary of pure and applied. And if all the observables that a theory predicts are identical to the observables that another theory predicts, those theories are physically identical. Differentiating between them from there is a matter of aesthetics, unless the theories have other predictions that are not currently observed - at which point it's a matter of aesthetics until observations can actually measure those predictions.
(Score: 1) by dingus on Saturday May 23 2015, @12:17AM
aaaaaah. Ok, I was confused by your first comment.
(Score: 2) by boristhespider on Saturday May 23 2015, @07:36AM
Sorry - I probably should have been clearer from the start. One thing I've learned is that whiskey isn't always conducive to clarity and conciseness :)